Nanoleaf LED bulb strives for efficiency at any cost, repeats mistakes of the CFL

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The Nanoleaf (Nanolight if you go by the Kickstarter page), a high-efficiency LED bulb, made waves in both Kickstarter and the LED lighting community at the start of this year when the project picked up over 5,000 backers and $273,000 in crowdfunding. The Nanoleaf didn’t just turn heads because of its unusual design, it was billed as the “most energy efficient [LED bulb] on the planet”. Not being an LED manufacturer and seemingly possessing no special technology, this was a rather incredible claim.

Producing 1600 lumens while running at 12W, the Nanoleaf was slated to put out an incredible 133 lumens-per-watts, or roughly double that of a standard consumer LED bulb. 1600 lumen (100W-equivalent) LED bulbs are still relatively rare, but Philips has one that sells for $40 and runs at 22W. (That’s 80.9 lumens-per-watt if you don’t have a calculator handy.) So how did this team of three use $273,278 to produce a bulb that — on paper — could wipe the floor with Philips’ long-awaited 100W-equivalent LED? As you probably guessed, once the product left the paper and arrived in people’s homes, things weren’t so simple.

These two images offer the best explanation I could think of. First, the 10W, 1200 lumen Nanoleaf LED bulb that I purchased.

You can see a significant difference between the two, even though these are just standard smartphone shots. Nanoleaf, curiously, did not include any mention of CRI or color temperature in its original Kickstarter posting. This, of course, wasn’t a great sign.

The intended color temperature was apparently 4000K, but the team ended up going with a less harsh 3500K. The decision was made clear in a comment on March 4 (funding closed on March 8). After some questions, it turned out that the CRI would be “about 70,” a fact that was added to the Kickstarter’s FAQ page at some point. That’s quite low for consumer lighting, with a color rendering index of 80 generally being seen as an acceptable starting point (thanks in part to 80 being the minimum number for Energy Star approval). It’s not clear what the Nanolight’s actual CRI is, but it’s not great.

The full FAQ answer goes as follows (emphasis not added): “There is always a trade off between efficiency and CRI. For the moment, NanoLight’s CRI is about 70 and we are working to increase this factor as much as we can WITHOUT decreasing the efficiency.”

Integrating sphere, used for lamp testing.

Increasing CRI without decreasing efficiency is a great concept, as would be driving more using the same amount of gas. The problem, as so often is the case, is that there are direct tradeoffs for these things. If you want more efficiency, that means less light quality (providing you don’t bring any technological improvements to the table). The Nanolight team could have hit a CRI of 80, 90, or even 95 easily enough with the right LEDs and/or the use of different phosphor, it would just have lost efficiency each step of the way. And, unfortunately, by the time the Nanoleaf got to an acceptable CRI level, the product would likely have been left with a bulb that performed just like a standard LED offering but that used their unorthodox origami design. In other words, the Nanoleaf is an interesting concept but you can’t get something for nothing.

It’ll be up to the project’s backers to decide if they feel the team was less than fully transparent about the performance of the bulb. As a backer, I can say that I’m disappointed with the end result and don’t feel it’s good enough for indoor use in a residential setting. This is exactly why LED lamp manufacturers like Philips, Cree, and Switch talk so much about light quality and resist getting into an efficiency arms race with one another — the companies know things will not end well. Maybe this all amounts to another problem with Kickstarted hardware, maybe it doesn’t. Most comments on the Nanoleaf’s page have to do with slow product delivery, not light quality.

Most consumers don’t know about things like CRI and color temperature, they just know when they see a light that doesn’t work for them, which is what happened with many CFLs and what larger manufacturers took pains to avoid with LEDs. So far it’s going well, but if we start demanding unrealistic efficiency numbers there is going to have to be a tradeoff that we’re not happy with.

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Agreed. I’ve been living with it for a few days (for testing purposes) and I’m about done.

some_guy_said

The Cree lights are absolutely great for dimmable lighting. They work well like incandescent, and don’t burn out or react funny like ‘dimmable’ flourescent.

However, I still use flourescent elsewhere in the house. I put up 4 cree bulbs in my bathroom once. While the cree lights put out generally good light, something about the color puts a very subtle, but deeply disconcerting and slightly washed out pallor to people.

Nisa Khan

Thank you for the useful description of your Cree lamps. Could you name the model of it or state the CRI and CCT of this bulb? I am investigating more deeply to explain where this undesirable lighting affect is coming from. Thanks.
Dr. Nisa Khan
(www.iem-led.com)

Mac

Yeah, I’ve had the same experience with other kickstarters. They promise the world, and the end product almost always has major quality issues. I think I’m done with backing future projects.

Spuffler

Seems like some people started with an idea but neglected to realize that illumination is a full engineering discipline which has seen a lot of development since inception. Forgive their naeve enthusiasm, but from here on, if you post at those kickstarted efforts, if you elect to financially support those efforts, then tell them hire staff who are professionals in the fields of interest. Efficacy, it’s not just for illumination any more.

Nisa Khan

Instead of putting blind money in developing supposedly better LED lamps, consumers, investors, and LED lamp designers would be better off getting a comprehensive background on LED lighting from my book, “Understanding LED
Illumination” by CRC Press (Taylor & Francis). It is available from amazon.com. Professor Stephen Y. Chou of Princeton University, a member of the National Academy of Engineering, called the book “the most comprehensive book in LED lighting”.

Dr. Nisa Khan
(www.iem-led.com)

Spuffler

I was thinking more that this development might be better off if it was to be guided by a member or fellow from IESNA. I’m not a member.

Nisa Khan

I know the top 5 IESNA fellows and past IESNA and CIE presidents. I know they will agree with me saying that while IESNA and CIE authorities can add to some lighting aspects of LEDs, they cannot explain or solve some of the deficiencies of LEDs. This has to do with LED’s intricate science involving compound semiconductors. My article on the introduction and motivation of my book will help, which you can find here:

I don’t understand how or why you get that green tone – my NanoLeaf is pure white, bright and beautiful. We have it in the fixture over our kitchen table (at one end of the room) and no longer need to use the 80’s sunshine ceiling when that one bulb is on. Mine is the 1200 lumen (75W) bulb, that yes, did take a lot longer to arrive than the original Kickstarter writeup promised, but I’m glad they tested and fixed and tested again to make sure we got an excellent product. And they took the time to keep us informed along the way. I’m ordering a 4 pack right now.

JohnCBriggs

Thank you for this great post. I was interested to know how that kickstarter worked out, and now I know. I will stick to the Cree, Philips, and Switch bulbs that I have.

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